This invention relates generally to electrically powered can openers. More specifically the invention relates to can openers of the type having power pierce and easily removable cutter mounting plates. The power pierce feature has been disclosed in U.S. Pat. No. 3,078,568, issued Feb. 26, 1963, and removability of the center mounting plate by means of a fixed latch and a cooperating fixed latch plate has been discussed in U.S. Pat. No. 3,688,400, issued Sept. 5, 1972. Both of the above patents are owned by the same assignee as in the subject invention.
Our invention includes a vertically oriented frame on which a cutter mounting plate and an interconnected hand piercing lever (which together comprises a compound piercing lever) are operably mounted. The hand piercing lever is pivotally attached to the can opener frame by a pin member which extends rearwardly from the piercing lever through a vertically oriented, oval-shaped aperture in the frame.
The cutter mounting plate is removably and pivotally attached to the can opener frame by a first pin member and a cooperating latching combination. The pin member extends rearwardly from the cutter mounting plate and engages a second frame aperture to facilitate pivotal rotation of the cutter mounting plate about said second frame aperture. The latching combination firmly but removably connects the cutter mounting plate to the can opener frame, precluding axial separation therebetween for a major portion of the cutter mounting plate pivot arc.
The latching combination includes a preferably stationary latch plate mounted to the can opener frame and a cooperating, selectively disengageable latch, mounted on the rear of the cutter mounting plate. When the cutter mounting plate is rotated to a preselected non-operative, angular position, the latch becomes disengaged from the latch plate and the cutter mounting plate may be easily removed. In an alternative embodiment of this invention the latch plate must be rotated slightly by the user (by depressing a suitable tab thereon) to facilitate disengagement of the cutter mounting plate. The latching combination also includes a second pin member which extends rearwardly from the cutter mounting plate to engage an arcuate slot in the can opener frame. A cap portion, located on the second pin member and having a slightly larger diameter than the pin member, cooperates to correctly locate the cutter mounting plate for easy removal or re-installation. The slot and pin assembly cooperate simultaneously with the aforementioned latch and latch plate combination to promote operative reliability. In another embodiment of this invention a capped pin member extends generally outwardly from the can opener surface (in which it is anchored) to engage an arcuate slot provided in a modified cutter mounting plate.
The hand piercing lever initiates and controls the movement of the cutter mounting plate. Accordingly, a third pin member also extends rearwardly from the cutter mounting plate toward the can opener frame and through an appropriately shaped slot in the piercing lever. The piercing lever is located between the cutter mounting plate and the can opener frame. Movement of the piercing lever thereby causes the cutter mounting plate to pivot to the desired operative position. Additionally, the hand piercing lever and the slot therein are constructed to facilitate positive re-engagement with the third cutter mounting plate pin member during re-attachment of the mounting plate to the can opener frame.
It is a primary object of this invention to provide a can opener having the aforementioned features wherein only minimal manual force is required to operate the piercing lever when piercing the end of an engage can. This is particularly important in regard to compact, small or miniature can openers since the forces developed by prior art designs tend to rotate or tilt smaller can openers during the can opening operation.
Accordingly, a compound piercing lever has been provided, which includes a pivoted hand piercing lever and a cooperating interconnected (removable) cutter mounting plate. Compounding has been accomplished, in part, by pivoting the hand piercing lever to the can opener frame and mechanically linking it to the cutter mounting plate (by means of a pin and slot) which in turn is pivoted to the frame. The resultant torque advantage from the lever combination facilitates the ease with which a can may be opened.
It is a further object of this invention to provide a can opener with the aforementioned compound piercing lever which includes an easily detachable cutter mounting plate. Accordingly, a detachable latching arrangement (described in U.S. Pat. No. 3,688,400) has been incorporated in the subject design, enabling the cutter mounting plate to be removed from the can opener frame when pivoted to a predetermined, substantially 43.degree. position by the cooperating hand piercing lever. However, to accomplish this, the cutter mounting plate and the hand piercing lever have been uniquely interconnected by means of the aforementioned pivot and slot assembly. The said assembly is constructed so that the hand piercing lever slot will automatically re-engage the cutter mounting plate pin as the can piercing lever is swung counterclockwise (when viewed from the front) to reattach the cutter mounting plate.
It is another object of this invention to provide, in a can opener having the previously described advantages, a compound piercing lever which will facilitate initiation of the motor means for power pierce operation. Accordingly, when force is developed by engaging a can end between the cutter wheel (on the cutter mounting plate) and the can feed wheel (on the frame), upwardly directed movement of the piercing lever (which is made possible by the oval shape of the aperture through which the piercing lever pivot pin extends) actuates an internally located electric switch.
It is yet another object of this invention to provide a can opener hand piercing lever of the character described which additionally will actuate the can opener motor means when the lever is moved slightly by the user when no can is being opened. This is of great advantage where cutlery grinding means, for example, is provided on the can opener in that the inclusion of an extra switch has thereby been avoided. Accordingly, the hand piercing lever has been constructed with a unique "heel portion" which fulcrums on a frame boss to effect the vertical upward movement of the hand lever necessary to activate the motor. This same hand lever construction may be used with can openers not featuring cutlery grinding means (or other motor driven accessories) so that production costs are minimized by the concomitant standardization.
It is yet another object of the subject invention to provide a can opener of the type described above which has the advantage of structure condensation. The construction of the compound piercing lever, which minimizes the tendency of a can opener to "tip over", and the inclusion of the multi-functional hand piercing lever, together with other previously described features, facilitates the ability to reduce the size of the can opener structure. As a direct result, costs of manufacturing and shipping the unit are significantly reduced. Further, the unit occupies less space when it is displayed in retail stores or used in the consumer's home.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.